1. Field of the Invention
This invention relates to machining units for performing machining operations on a workpiece and, more particularly, to a system for processing elongate workpieces utilizing a plurality of the machining units. The invention is also directed to a method for processing elongate workpieces utilizing the system.
2. Background Art
In machining facilities, it is desirable to have the capability to perform multiple machining operations in an efficient manner while minimizing space requirements for the machining equipment. Typically, machine tool assemblies/machining units are arranged on a floor on one level. Most commonly, the machine tool assemblies are oriented horizontally. Floor space planning is carried out with the understanding that the footprint of each horizontally situated machine tool assembly will dictate the amount of floor space required for a particular machine tool assembly. Space above the footprint that is not occupied by the machine tool assembly is for all practical purposes wasted space.
It is known to orient machine tool assemblies vertically to better utilize vertically available space. One example of such an arrangement is shown in my U.S. Pat. No. 6,081,986. While this arrangement does make a better utilization of vertical space, there are drawbacks with this arrangement. First of all, some machine tool assemblies may be more prone to deformation if oriented in other than a horizontal direction. That is, many systems are configured in a pyramidal construction so that stability and accuracy are maintained by building components with decreasing mass from the base up. The vertical orientation of this type of machine tool assembly may cause the misalignment of cooperating components that could detract from system performance.
As with horizontal systems, the space above the vertically oriented individual machine tool assemblies is for all practical purposes wasted.
While ideally many machining operations are performable simultaneously under one roof, the number of such operations is generally limited by the surface area of a floor on which the machine tool assemblies are supported.
In one form, the invention is directed to a system for processing elongate workpieces. The system consists of a first machining unit for performing a first processing operation on an elongate workpiece that is situated at a first location and a second machining unit for performing a second processing operation on an elongate workpiece that is situated at a second location that is vertically spaced from the first location. The system further consists of a first supply unit on which a plurality of elongate workpieces can be placed in a stored position. A transfer assembly engages an elongate workpiece in a stored position and selectively delivers an elongate workpiece engaged by the transfer assembly to one of the first and second locations.
In one form, the transfer assembly includes a shuttle assembly which is vertically movable between a first position, from where an elongate workpiece on the shuttle assembly can be delivered to the first location, and a second position, from where an elongate workpiece on the shuttle assembly can be delivered to the second location.
The transfer assembly may further include a first loading unit for directing the elongate workpieces from the stored position to a holding position on the shuttle assembly.
The shuttle assembly may further include an elongate workpiece holder that is repositionable between a conveying position and a first transfer position.
The system may include a first guide surface to which an elongate workpiece in the holding position can be delivered and guided toward the first location with the shuttle assembly in the first position. The first guide surface may decline toward the first location.
In one form, the elongate workpiece holder consists of at least one surface which defines a receptacle for an elongate workpiece in the holding position with the workpiece holder in the conveying position and which guides movement of the elongate workpiece in the holding position onto the first guide surface as an incident of the workpiece holder changing from the conveying position toward the first transfer position.
The elongate workpiece holder may be pivotable between the conveying and transfer positions.
The system may further include a third machining unit for performing a third processing operation on an elongate workpiece that is at a third location spaced from the first and second locations.
In one form, the elongate workpiece holder is repositionable to a second transfer position. The system includes a third guide surface with the at least one surface on the elongate workpiece holder guiding movement of an elongate workpiece in the holding position onto the third guide surface as an incident of the workpiece holder changing from the conveying position toward the second transfer position.
The first and third locations may be at substantially the same height.
The system may further include a guide assembly for guiding vertical movement of the shuttle assembly between the first and second positions.
In one form, the loading unit consists of a pickup shoulder that is moveable between a pickup position and a release position, with the pickup shoulder engaging an elongate workpiece in the stored position and causing movement of an elongate workpiece in the stored position toward the elongate workpiece holder as an incident of the pickup shoulder moving from the pickup position toward the release position.
The shoulder may be pivotable between the pickup and release positions.
In one form, the supply unit consists of an inclined feeding surface along which elongate workpieces are urged by gravitational force toward a pickup location.
In one form, the first loading unit has a blocking surface which blocks movement of an elongate workpiece into the pickup location as the pickup shoulder is moved with a workpiece from the pickup position into the release position.
In one form, there is a stop shoulder at the first guide surface to which an elongate workpiece moving downwardly along the first guide surface abuts to maintain the elongate workpiece which has moved downwardly along the first guide surface consistently in a predetermined position against the stop shoulder.
In one form, the transfer assembly includes a first guide surface which is inclined so as to guide elongate workpieces from the first supply unit toward the first location and a second guide surface which is inclined so as to guide elongate workpieces from the first supply unit toward the second location.
With the shuttle assembly in the first position, a workpiece thereon can be delivered to against the first guide surface for movement thereagainst under gravitational force toward the first location. With the shuttle assembly in the second position, an elongate workpiece thereon can be delivered to against the second guide surface for movement thereagainst under gravitational force toward the second location.
The system may further include a pusher assembly for directing a workpiece into operative relationship with the first machining unit.
In one form, the first machining unit has a rotary operating axis and the pusher assembly pushes an elongate workpiece in a line that is substantially coincident with the rotary operating axis.
The system may include at least one elongate workpiece in a stored position on the first supply unit.
The invention is also directed to a method for processing elongate workpieces, including the steps of: storing a plurality of elongate workpieces on a first supply unit; delivering a first elongate workpiece from the first supply unit to a first location; performing a first processing operation on the first elongate workpiece at the first location; delivering a second elongate workpiece from the first supply unit to a second location that is vertically spaced from the first location; and performing a second processing operation on the second elongate workpiece at the second location.
The method may further include the steps of removing the first elongate workpiece from the first supply unit and blocking removal of another of the plurality of elongate workpieces from the first supply unit.
The step of delivering the first elongate workpiece may involve delivering the first elongate workpiece to against a first inclined guide surface so that the first elongate workpiece moves against the first inclined guide surface under the force of gravity toward the first location.
The step of delivering the second elongate workpiece may involve delivering the second elongate workpiece to against a second inclined guide surface so that the second elongate workpiece moves against the second inclined guide surface under the force of gravity toward the second location.
The step of storing a plurality of elongate workpieces may involve storing a plurality of workpieces on an inclined feeding surface so that the plurality of elongate workpieces are urged by gravitational forces into an accumulated state, one against the other.
The method may further include the steps of guiding the first elongate workpiece from the first supply unit to a first workpiece holder.
The method may further include the step of repositioning the first workpiece holder to thereby direct the first elongate workpiece from the first workpiece holder toward the first location.
The method may further include the steps of directing a third elongate workpiece from the first supply unit to the first workpiece holder and repositioning the first workpiece holder to thereby direct the third elongate workpiece from the first workpiece holder toward a third location.
The method may further include the steps of delivering a third elongate workpiece to the third location and at the third location performing a third processing step on the third elongate workpiece.
The method may include the steps of directing the first elongate workpiece past the first workpiece holder to a second workpiece holder and repositioning the second workpiece holder to thereby direct the first elongate workpiece from the second workpiece holder toward the first location.
The method may include the steps of directing a third elongate workpiece past the first workpiece holder to a second workpiece holder and repositioning the second workpiece holder to thereby direct the third elongate workpiece from the second workpiece holder toward a third location.
The method may include the steps of placing the first workpiece holder in a holding state, directing the first elongate workpiece into a holding position on the first workpiece holder, changing the first workpiece holder from the holding state into a release state, and repositioning the first workpiece holder so that with the first workpiece holder in the release state the first elongate workpiece is directed toward the first location.
The method may include the steps of placing the first workpiece holder into a release state and guiding a third elongate workpiece through the first workpiece holder to a holding position on the second workpiece holder.
The method may further include the step of repositioning the second workpiece holder to thereby direct the third elongate workpiece toward a third location.